It is understood that rather than a targeted attack on parade-goers, Mr Brooks Jr was fleeing the scene of another incident – possibly a knife fight.

Mr Brooks Jr was a vocal Black Lives Matter supporter and screenshots from a now-deleted Facebook page appear to show his disapproval of the Kyle Rittenhouse verdict – where the teenager was cleared over the killing of two BLM protesters. Five law enforcement officials told NBC there was no immediate connection to terrorism or the Rittenhouse verdict.

On his soundcloud page, Mr Brooks wrote: “Born nd raised in Milwaukee, WI in the dangerous west side neighborhood of Washington Park, Fly turn to the streets at a very young age..after multiple legal battles, Fly started turning the life he lived in the streets into music, with his 1st mixtape released in the summer of 2014..now considered the best underground artist in his city, keep looking out for more big moves by the best Milwaukee artist of this era..”

The incident has caused shock and distress both in the local community and America at large. Videos from Waukesha showed a red car hurtling past onlookers and eventually into the back of a marching band and several dance groups, sending people scattering.

“There were pom-poms and shoes and spilled hot chocolate everywhere,” said Corey Montiho, the mother of a girl whose dance team was hit by the SUV. 

“I had to go from one crumpled body to the other to find my daughter,” she told the Milwaukee Journal Sentinel.